PROFESSOR T. S. 0. LOWE OBSERVING THE BATTLE OF SEVEN PINES FROM HIS BALLOON “ INTREPID” ON THE NORTH SIDE OF THE CHICKAHOMINY. taneously at Mechaniesville, Meadow Bridge, and above, and pushed down the left bank, along the roads leading to Beaver Dam Creek. In accordance with directions previously given, the outposts watching the access to the crossings fell back after slight resistance to their already designated position on the east bank of Beaver Dam Creek, destroying the bridges as they retired. After passing Mechaniesville the attacking forces were divided, a portion taking the road to the right to Ellerson’s Mill, while the larger body directed their march to the left into the valley of Beaver Dam Creek, upon the road covered by Reynolds. Apparently unaware, or regardless, of the great danger in their front, this force moved on with animation and confidence, as if going to parade, or engaging in a sham battle. Suddenly, when half-way down the bank of the valley, our men opened upon it rapid volleys of artillery and infantry, which strewed the road and hillside with hundreds of dead and wounded, and drove the main body of the survivors back in rapid flight to and beyond Mechaniesville. So rapid was the fire upon the enemy’s huddled masses clambering back up the hill, that some of Reynolds’s ammunition was exhausted, and two regiments were relieved by the 4th Michigan and 14th New York of Griffin’s brigade. On the extreme right a small force of the enemy secured a foothold on the east bank, but it did no harm, and retired under cover of darkness. The forces which were directed against Seymour at Ellerson’s Mill made little progress. Seymour’s direct and Reynolds’s flank fire soon arrested them and drove them to shelter, suffering even more disastrously than those who had attacked Reynolds. Late in the afternoon, greatly strengthened, they renewed the attack with spirit and energy, some ville, and west to Meadow Bridge, largely concealed from view the forces gathered to execute an evidently well-planned and well-prepared attack upon my command. ... In the northern and western horizon vast clouds of dust arose, indicating the movements of Jackson’s advancing forces. They were far distant, and we had reason to believe that the obstacles to their rapid advance, placed in their way by detachments sent for that purpose, would prevent them from making an attack that day. As before stated, we did not fear Lee alone; we did fear his attack, combined with one by Jackson on our flank. . . . About 2 o’clock p. m., on the 26th, the boom of a single cannon in the direction of Mechaniesville resounded through our camps. This was the signal which had been agreed upon, to announce the fact that the enemy were crossing the Chiekahom-iny. The curtain rose; the stage was prepared for the first scene of the tragedy. At once tents were struck, ^wagons packed and sent to the rear to cross to the right bank of the Chiekahominy. The several divisions were promptly formed, and took the positions to which they had previously been assigned. General McCall assumed command at Beaver Dam Creek; Meade joined him, taking position behind Seymour; Martindale and General Charles Griffin, of Morell’s division, went, respectively, to the right and rear of Reynolds; Butterfield was directed to support General Cooke’s, and subsequently Martindale’s right, while Sykes was held ready to move wherever needed. Reynolds and Seymour prepared for action and concealed their men. About 3 o’clock the enemy, under Longstreet, D. H. and A. P. Hill, in large bodies commenced rapidly to cross the Chiekahominy almost simul-112 sent him, had informed him that Jackson was in the immediate vicinity, ready to unite with Lee in an attack upon my command. . . . Reynolds, who had special charge of the defenses of Beaver Dam Creek and of the forces at and above Mechanics-ville, was at once informed of the situation. He prepared to give our anticipated visitors a warm welcome. . . . Early on the 26th I was informed of a large increase of forces opposite Reynolds, and before noon the Confederates gave evidence of their intention to cross the river at Meadow Bridge and Mechaniesville, while from our cavalry scouts along the Virginia Central Railroad came reports of the approach from the north of large masses of troops. Thus the attitude of the two armies toward each other was changed. Yesterday, McClellan was rejoicing over the success of his advance toward Richmond, and he was confident of reinforcement by McDowell. To-day, all the united available forces in Virginia were to be thrown against his right flank, which was not in a convenient position to be supported. The prizes now to be contended for were: on the part of McClellan, the safety of his right wing, protection behind his intrench-ments with the possibility of being able to remain there, and the gain of sufficient time to enable him to effect a change of base to the James; on the part of Lee, the destruction of McClellan’s right wing, and, by drawing him from his intrenchments and attacking him in front, the raising of the siege of Richmond. The morning of Thursday, June 26th, dawned clear and bright, giving promise that the day would be a brilliant one. The formation of the ground south of the Chiekahominy opposite Mechanics- PHILIP ST. GEORGE COOKE, BREVET MAJOR-GENERAL, U. S. A. From a photograph. already aroused, we felt that we should be in peril. But as Jackson had thus far prevented McDowell from joining us, we trusted that McDowell, Banks, and Prdmont, who had been directed to watch Jack-son, would be able to prevent him from joining Lee, or, at least, would give timely warning of his escape from their front and follow close upon his heels. With McClellan’s approval, my command was distributed as follows: General Geo. G. Meade’s brigade of General Geo. A. McCall’s division of Pennsylvania Reserves was posted at Gaines’s house, protecting a siege-battery controlling New Bridge; Generals John F. Reynolds’s and Truman Seymour’s brigades held the rifle-pits skirting the east bank of Beaver Dam Creek and the field-works covering the only crossings near Mechaniesville and Ellerson’s Mill. . . . Cooke’s cavalry, near Cold Harbor, guarded the right rear and scouted toward Hanover Court House, while Morell’s and Sykes’s divisions were conveniently camped so as to cover the bridge-crossings and to move quickly to any threatened point. Such was the situation on the 24th of June, when, at midnight, General McClellan telegraphed me that a pretended deserter, whom I had that day UNION ARTILLERY AT MECHANICSVILLE SHELLING THE CONFEDERATE WORKS SOUTH OF THE CHICKAHOMINY.